I'm doing a repair on an eMachines system with an ASRock K7VM3. The eMachines systems for the Socket A platform were very poor in terms of motherboards and a crop of machines were turning up with Dead boards. However, I can replace the boards in the machines with same chipset in order to keep the driver stability on boot to desktop.

There are not that many Socket A motherboards available to purchase from and I was left with very little choice but to just purchase an ASRock K7VM3. The ASRock for some odd reason has a jumper to set the 5vSB for keyboard and Mouse. However, the board shipped in the 5vSB jumper selection rather than 5v jumper selection. That configuration ate not 1 keyboard, but upto 5 keyboards by frying them with the 5vSB. So, I RMA the board back, and now with replacement in, the board doesn't boot into POST. It just idles until I shut it off. Although this one isn't eating keyboards anymore. It's not even making to POST.

I did the usual diagnostics that one would normally do. However, I don't like the design of this board and feel very jaded at the moment as ASRock boards I've built with in the past never had such a jumper or tediousness to setup out of the box.

Has anyone else had this board and the same issues or similar with booting process? The first board booted to Desktop, but ate the keyboards.

The 5Vsb only eats keyboards and mice if the voltage isn't OK, or if the keyboard or mouse is poorly designed and doesn't like being powered all the time. My guess is on the former. Your second board being a no-starter is further evidence for a power supply problem.